Publication 1763-RM001C-EN-P - October 2009
86
Programming Instructions Overview
Indirect Addressing of Bit
•
Address: B3/[B25:0]
•
Description: In this example, the element to be used for the
indirection is B25:0. The data in B25:0 defines the bit within file B3.
If the value of location B25:0 = 1017, the XIC instruction is
processed using B3/1017.
These are only some of the examples that can be used; others include:
•
File and Element Indirection: N[N10:0]:[N25:0]
•
Input Slot Indirection: I1:[N7:0].0
Each group of instructions may or may not allow indirection. Please
review the compatibility table for each instruction to determine which
elements within an instruction support indirection.
TIP
If a number larger than 4096 (or larger than the
number of elements in the data file) is placed in
B25:0 in this example, data integrity cannot be
guaranteed. Exceeding the number of elements in
the data file would cause the file boundary to be
crossed.
IMPORTANT
You must exercise extreme care when using indirect
addressing. Always be aware of the possibility of
crossing file boundaries or pointing to data that was not
intended to be used.
0002
B3:0
[B25:0]
B3:0
10
0003
END
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